1. Field of the Invention
The present invention relates to an internal combustion engine having a combustion heater.
2. Related Background Art
It is required that a warm-up of an internal combustion engine be speeded up at a cold time, and it is desirable to enhance a performance of a car room heater of a vehicle mounted with the internal combustion engine.
This being the case, for example, Japanese Patent Application Laid-Open Publication No. 62-75069 discloses a technology of increasing a temperature of the so-called engine cooling water contained in an internal combustion engine body by utilizing combustion heat emitted from a combustion heater provided in a intake system separately from an internal combustion engine body and thereby speeding up the warm-up thereof and enhancing the performance of the car room heater.
Such an effect can be expected on one hand, however, in the internal combustion engine having the combustion heater, there might arise a serious concern about a thermal damage to a intake system structure on the other hand because of an excessive rise in a intake system temperature due to an influence by combustion heat emitted from the combustion heater.